York 97% Modulating Gas Furnace: YP9C

Re: Flashing Code 5

Flashing Code 5 = Rollout Switch or Condensate Pressure Switch

The rollout switches and the condensate pressure switch are wired in series, so either switch opening during a call for heat will cause a Code 5.

CHECKOUT:

1. Check Rollout Switches

• Reset the furnace by cycling power.
• Start a call for heat by energizing "W".
• Monitor the LED on the furnace board for lockout indication.
  • If board immediately goes into a Code 5, press the reset button on each rollout limit and retry.

2. Monitor Condensate Switch Pressure

• Connect a pressure gauge to the low pressure switch hose.
• Monitor the pressure as the system operates.
  • If the pressure drop below or near 0.20" w.c. suspect clogged drain --> Step 3. Check Condensate Drainage

3. Check Condensate Drainage

• Check drain hoses from vent coupling.
  • If installed horizontally, make sure drains are sloped downward.
  • Make sure vent coupling is installed with arrow pointing away from furnace.
• Check drain hoses from inducer and collector box.
  • Make sure all drain hoses are clear and have a downward slope.
• ! Make sure there is an "Air-Gap" in the PVC drain immediately upon exiting the furnace !
  • The collector box is internally-trapped.
  • Any trap in the drain after the collector box before an air gap will cause drainage issues.
• In extreme cold conditions be cautious of Frozen Drains.